Vitamin B12

(cobalamin)

DRI (RDA or AI for Adults)

2.4 mcg. Pregnancy: 2.6 mcg. Lactation: 2.8 mcg.

Adult Maintenance - Therapeutic Range

100 - 1,000 mcg

Major Sources (110 mcg to 1 mcg per serving)

Beef liver, clams, veal liver, beef kidney, veal kidney, turkey liver, oysters, chicken liver, beef heart, herring, crab, trout, pollock, catfish, salmon, beef, lamb, tuna, shrimp, lowfat yogurt. Vegans require supplement.

Non-Therapeutic Importance

Involved in the metabolism of single-carbon fragments; essential for biosynthesis of nucleic acids, nucleoproteins, and red blood cells; role in metabolism of nervous tissue; involved with folate metabolism; related to growth.

Deficiency Symptoms

Degeneration of peripheral nerves
Glossitis
Pernicious anemia
Skin hypersensitivity

Increased Risk for Deficiency

Alcoholism
Celiac and tropical sprue
Diverticulosis
Ileitis
Lack of intrinsic factor secretion: gastrectomy; destruction of gastric mucosa
Vegetarians

Possible Therapeutic Applications

CONSULT WITH A HEALTH PROFESSIONAL FIRST: Vitamin B12 works with folic acid in reducing homocysteine, a risk factor for heart disease. Supplementation may prevent, correct deficiencies caused by, or be helpful with, the following conditions:

Acquired Immunodeficiency Syndrome (AIDS, HIV)
Aging
Alcoholism
Allergies (allergic rhinitis, hay fever)
Anxiety
Asthma
Atherosclerosis (heart disease)
Celiac Disease
Cerebrovascular Disease (including stroke)
Chronic Fatigue Syndrome (CFS, CFIDS)
Crohn's Disease
Diabetes
Eating Disorders (anorexia, bulimia)
Glaucoma
Hepatitis
Herpes Zoster (shingles)
Hypercholesterolemia (high cholesterol)
Immunodepression (immune function)
Infection (colds, flu, etc.)
Infertility (female)
Infertility (male)
Inflammation (including bursitis)
Lupus (SLE)
Memory Loss (Alzheimer's disease, dementia)
Multiple Sclerosis (MS)
Osteoarthritis
Osteoporosis
Psoriasis
Retinopathy
Tinnitus